Android 回收器视图不显示来自firebase的图像，但显示文本
我正在尝试使用Recycler View从firebase获取和显示图像，但显示了图像的名称，但未显示图像。我已经检查了堆栈上几乎所有可用的内容，但我失败了，这就是为什么再次问类似问题的原因Android 回收器视图不显示来自firebase的图像，但显示文本,android,firebase,android-layout,android-fragments,Android,Firebase,Android Layout,Android Fragments,我正在尝试使用Recycler View从firebase获取和显示图像，但显示了图像的名称，但未显示图像。我已经检查了堆栈上几乎所有可用的内容，但我失败了，这就是为什么再次问类似问题的原因 public class ImagesActivity extends AppCompatActivity{ private RecyclerView mRecyclerView; private ImageAdapter mAdapter; private ProgressBar
public class ImagesActivity extends AppCompatActivity{
private RecyclerView mRecyclerView;
private ImageAdapter mAdapter;
private ProgressBar mProgressCircle;
private DatabaseReference mDatabaseRef;
private List<Upload> mUploads;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_images);
//FirebaseAuth mAuth = FirebaseAuth.getInstance();
mRecyclerView = findViewById(R.id.recycler_view);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this));
mRecyclerView.setAdapter(mAdapter);
mProgressCircle = findViewById(R.id.progress_circle);
mUploads = new ArrayList<>();
mDatabaseRef = FirebaseDatabase.getInstance().getReference("uploads");
mDatabaseRef.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
mUploads.clear();
for (DataSnapshot postSnapshot : dataSnapshot.getChildren()) {
Upload upload = postSnapshot.getValue(Upload.class);
mUploads.add(upload);
}
mAdapter = new ImageAdapter(ImagesActivity.this, mUploads);
mRecyclerView.setAdapter(mAdapter);
mProgressCircle.setVisibility(View.INVISIBLE);
}
@Override
public void onCancelled(DatabaseError databaseError) {
Toast.makeText(ImagesActivity.this, databaseError.getMessage(), Toast.LENGTH_SHORT).show();
mProgressCircle.setVisibility(View.INVISIBLE);
}
});
}
}
public类MainActivity扩展了AppCompatActivity{
私有静态最终整数选取图像请求=1；
私人按钮mButtonChooseImage；
专用按钮MBUTONUPLOAD；
私有文本视图MTEXTVIEWSHOW上传；
私有EditText mEditTextFileName；
私有图像视图mImageView；
私人ProgressBar mProgressBar；
私有Uri-mimageri；
私有存储参考mStorageRef；
私有数据库引用mDatabaseRef；
专用存储任务mUploadTask；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
FirebaseAuth mAuth=FirebaseAuth.getInstance（）；
mButtonChooseImage=findviewbyd（R.id.button\u choose\u image）；
mButtonUpload=findviewbyd（R.id.button\u上传）；
mTextViewShowUploads=findviewbyd（R.id.text\u view\u show\u uploads）；
mEditTextFileName=findviewbyd（R.id.edit\u text\u file\u name）；
mImageView=findviewbyd（R.id.image\u视图）；
mProgressBar=findviewbyd（R.id.progress\u bar）；
mStorageRef=FirebaseStorage.getInstance（）.getReference（“上传”）；
mDatabaseRef=FirebaseDatabase.getInstance（）.getReference（“上载”）；
mButtonChooseImage.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
openFileChooser（）；
}
});
mButtonUpload.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
if（mUploadTask！=null&&mUploadTask.isInProgress（））{
Toast.makeText（MainActivity.this，“正在上载”，Toast.LENGTH_SHORT.show（）；
}否则{
上传文件（）；
}
}
});
mTextViewShowUploads.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
openImagesActivity（）；
}
});
}
私有void openFileChooser（）{
意图=新意图（）；
intent.setType（“image/*”）；
intent.setAction（intent.ACTION\u GET\u CONTENT）；
startActivityForResult（意图、拾取图像请求）；
}
@凌驾
受保护的void onActivityResult（int请求代码、int结果代码、意图数据）{
super.onActivityResult（请求代码、结果代码、数据）；
如果（requestCode==PICK\u IMAGE\u REQUEST&&resultCode==RESULT\u OK
&&数据！=null&&data.getData（）！=null）{
mimageri=data.getData（）；
毕加索.with（this）.load（mimageri）.into（mImageView）；
}
}
私有字符串getFileExtension（Uri）{
ContentResolver cR=getContentResolver（）；
MimeTypeMap mime=MimeTypeMap.getSingleton（）；
返回mime.getExtensionFromMimeType（cR.getType（uri））；
}
私有void上传文件（）{
if（mimageri！=null）{
StorageReference fileReference=mStorageRef.child（System.currentTimeMillis（）
+“+getFileExtension（mimageri））；
mUploadTask=fileReference.putFile（mimageri）
.addOnSuccessListener（新的OnSuccessListener（）{
@凌驾
成功时公共无效（UploadTask.TaskSnapshot TaskSnapshot）{
Handler=newhandler（）；
handler.postDelayed（新的Runnable（）{
@凌驾
公开募捐{
mProgressBar.setProgress（0）；
}
}, 500);
Toast.makeText（MainActivity.this，“上载成功”，Toast.LENGTH_LONG.show（）；
Upload Upload=新上载（mEditTextFileName.getText（）.toString（）.trim（），
taskSnapshot.getUploadSessionUri（）.toString（））；
字符串uploadId=mDatabaseRef.push（）.getKey（）；
mDatabaseRef.child（uploadId）.setValue（upload）；
}
})
.addOnFailureListener（新的OnFailureListener（）{
@凌驾
public void onFailure（@NonNull异常e）{
Toast.makeText（MainActivity.this，e.getMessage（），Toast.LENGTH_SHORT）.show（）；
}
})
.addOnProgressListener（新的OnProgressListener（）{
@凌驾
public void onProgress（UploadTask.TaskSnapshot TaskSnapshot）{
双进度=（100.0*taskSnapshot.GetByTestTransferred（）/taskSnapshot.getTotalByteCount（））；
mProgressBar.setProgress（（int）progress）；
}
});
}否则{
Toast.makeText（这是“未选择文件”，Toast.LENGTH_SHORT）.show（）；
}
}
私有void openImagesActivity（）{
Intent Intent=新Intent（这是ImagesActivity.class）；
星触觉（意向）；
}
}
获取错误：E/RecyclerView:未连接适配器；跳过布局最终解决了问题，实际上，从firebase获取的URL中存在问题…上面的代码没有问题。最终解决了问题，实际上，从firebase获取的URL中存在问题…上面的代码有问题
class ImageAdapter extends RecyclerView.Adapter<ImageAdapter.ViewHolder> {
private List<Upload>list_data;
private Context ct;
public ImageAdapter(Context context, List<Upload> uploads) {
this.list_data = uploads;
this.ct = context;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.image_item,parent,false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
Upload ld=list_data.get(position);
holder.tvname.setText(ld.getName());
Picasso.with(ct).load(ld.getImageUrl()).into(holder.imageView);
}
@Override
public int getItemCount() {
return list_data.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private ImageView imageView;
private TextView tvname;
public ViewHolder(View itemView) {
super(itemView);
imageView=(ImageView)itemView.findViewById(R.id.image_view_upload);
tvname=(TextView)itemView.findViewById(R.id.text_view_name);
}
}
}
public class Upload {
private String name;
private String imageUrl;
public Upload() {
}
public Upload(String name, String imageUrl) {
if (name.trim().equals("")) {
name = "No Name";
}
this.name = name;
this.imageUrl = imageUrl;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getImageUrl() {
return imageUrl;
}
public void setImageUrl(String imageUrl) {
this.imageUrl = imageUrl;
}
}
public class MainActivity extends AppCompatActivity {
private static final int PICK_IMAGE_REQUEST = 1;
private Button mButtonChooseImage;
private Button mButtonUpload;
private TextView mTextViewShowUploads;
private EditText mEditTextFileName;
private ImageView mImageView;
private ProgressBar mProgressBar;
private Uri mImageUri;
private StorageReference mStorageRef;
private DatabaseReference mDatabaseRef;
private StorageTask mUploadTask;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FirebaseAuth mAuth = FirebaseAuth.getInstance();
mButtonChooseImage = findViewById(R.id.button_choose_image);
mButtonUpload = findViewById(R.id.button_upload);
mTextViewShowUploads = findViewById(R.id.text_view_show_uploads);
mEditTextFileName = findViewById(R.id.edit_text_file_name);
mImageView = findViewById(R.id.image_view);
mProgressBar = findViewById(R.id.progress_bar);
mStorageRef = FirebaseStorage.getInstance().getReference("uploads");
mDatabaseRef = FirebaseDatabase.getInstance().getReference("uploads");
mButtonChooseImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openFileChooser();
}
});
mButtonUpload.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (mUploadTask != null && mUploadTask.isInProgress()) {
Toast.makeText(MainActivity.this, "Upload in progress", Toast.LENGTH_SHORT).show();
} else {
uploadFile();
}
}
});
mTextViewShowUploads.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
openImagesActivity();
}
});
}
private void openFileChooser() {
Intent intent = new Intent();
intent.setType("image/*");
intent.setAction(Intent.ACTION_GET_CONTENT);
startActivityForResult(intent, PICK_IMAGE_REQUEST);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == PICK_IMAGE_REQUEST && resultCode == RESULT_OK
&& data != null && data.getData() != null) {
mImageUri = data.getData();
Picasso.with(this).load(mImageUri).into(mImageView);
}
}
private String getFileExtension(Uri uri) {
ContentResolver cR = getContentResolver();
MimeTypeMap mime = MimeTypeMap.getSingleton();
return mime.getExtensionFromMimeType(cR.getType(uri));
}
private void uploadFile() {
if (mImageUri != null) {
StorageReference fileReference = mStorageRef.child(System.currentTimeMillis()
+ "." + getFileExtension(mImageUri));
mUploadTask = fileReference.putFile(mImageUri)
.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
@Override
public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
mProgressBar.setProgress(0);
}
}, 500);
Toast.makeText(MainActivity.this, "Upload successful", Toast.LENGTH_LONG).show();
Upload upload = new Upload(mEditTextFileName.getText().toString().trim(),
taskSnapshot.getUploadSessionUri().toString());
String uploadId = mDatabaseRef.push().getKey();
mDatabaseRef.child(uploadId).setValue(upload);
}
})
.addOnFailureListener(new OnFailureListener() {
@Override
public void onFailure(@NonNull Exception e) {
Toast.makeText(MainActivity.this, e.getMessage(), Toast.LENGTH_SHORT).show();
}
})
.addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
@Override
public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
double progress = (100.0 * taskSnapshot.getBytesTransferred() / taskSnapshot.getTotalByteCount());
mProgressBar.setProgress((int) progress);
}
});
} else {
Toast.makeText(this, "No file selected", Toast.LENGTH_SHORT).show();
}
}
private void openImagesActivity() {
Intent intent = new Intent(this, ImagesActivity.class);
startActivity(intent);
}
}
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="8dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/text_view_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:text="Name"
android:textColor="@android:color/black"
android:textSize="20sp" />
<ImageView
android:id="@+id/image_view_upload"
android:layout_width="match_parent"
android:layout_height="300dp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="8dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="@+id/text_view_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:layout_marginBottom="8dp"
android:layout_marginTop="8dp"
android:text="Name"
android:textColor="@android:color/black"
android:textSize="20sp" />
<ImageView
android:id="@+id/image_view_upload"
android:layout_width="match_parent"
android:layout_height="300dp" />
</LinearLayout>
</androidx.cardview.widget.CardView>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:padding="16dp"
tools:context="ranjan.shashi.firebaseuploadretrieveimages.MainActivity">
<Button
android:id="@+id/button_choose_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Choose file" />
<EditText
android:id="@+id/edit_text_file_name"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_toEndOf="@+id/button_choose_image"
android:hint="Enter file name" />
<ImageView
android:id="@+id/image_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/progress_bar"
android:layout_below="@id/edit_text_file_name"
android:layout_marginTop="16dp" />
<ProgressBar
android:id="@+id/progress_bar"
style="@style/Widget.AppCompat.ProgressBar.Horizontal"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_above="@+id/button_upload"
android:layout_alignParentStart="true"
android:layout_marginBottom="16dp" />
<Button
android:id="@+id/button_upload"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
android:text="Upload" />
<TextView
android:id="@+id/text_view_show_uploads"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/button_upload"
android:layout_alignTop="@+id/button_upload"
android:layout_marginStart="25dp"
android:layout_toEndOf="@+id/button_upload"
android:gravity="center"
android:text="Show Uploads"
android:textSize="16sp" />
</RelativeLayout>